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Updated: Jul 18, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
Fascicular tachycardia sensitive to calcium antagonists
This study identifies an unusual reentrant tachycardia mechanism in the posterior fascicle of the left bundle branch. Calcium antagonists effectively managed these tachycardias, suggesting a novel therapeutic target for right bundle branch block patients.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Arrhythmias
Background:
- Recurrent tachycardias can present with complex electrocardiographic findings.
- Right bundle branch block with left axis deviation necessitates detailed electrophysiological investigation.
Observation:
- Five patients with recurrent tachycardias and right bundle branch block with left axis deviation were studied.
- Tachycardia induction revealed specific cycle lengths and significant leftward axis shifts.
- Ventriculoatrial dissociation was observed, and tachycardias responded to calcium antagonists.
Findings:
- An unusual reentrant tachycardia mechanism involving the posterior fascicle of the left bundle branch was identified.
- Tachycardia characteristics included specific QRS morphology, axis changes, and HV intervals.
- Calcium antagonists demonstrated efficacy in terminating or slowing these tachycardias.
Implications:
- These findings suggest a distinct arrhythmogenic substrate in the posterior fascicle.
- Understanding this mechanism may lead to improved diagnostic and therapeutic strategies for specific tachycardia types.
- Calcium antagonists represent a potential treatment option for these complex tachycardias.
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